Anterior to 1540 we have no signed and dated example, and should therefore be reduced to the position of entire ignorance as to their previous productions but for the work of the indefatigable archæologist Giambattista Passeri. Born in 1694 at Farnese in the Campagna di Roma (where his father, of a patrician family of Pesaro, practised as a physician) and educated at Rome, he subsequently settled in his parental city and published the “Istoria delle pitture in Maiolica fatte in Pesaro e in luoghi circonvicini,” in 1758. To him we are indebted for the notice of the potters above alluded to, and in his work he gives us an account of the mode pursued in the manufacture, much of which however he appears to have derived from the earlier manuscript of Piccolpasso. He tells us that the large early bacili enriched with a _madreperla_ lustre were the produce of Pesaro; and in corroboration states that many of them are painted with the coats of arms and portraits of the members of noble Pesarese families, instancing one with the arms of the “Bergnana” family then preserved in the Casa Olivieri. It has been objected that Passeri was influenced by local partiality in favour of the native city of his family, and that he ascribed to her furnaces what may in equal likelihood have been produced at Gubbio or Diruta; and the discovery of a few pieces of lustred ware, marked as the produce of the latter _Castello_ in the middle of the 16th century, was hailed by several critics as conclusive evidence against his assertion. It appears to the writer that such evidence is equally unsatisfactory, inasmuch as the works in question were produced some century and a half anterior to the earliest dated piece of Diruta ware. Passeri wrote in the middle of the last century, when the art was no longer in existence and its specimens only preserved in the cabinets of the curious; but he was a man of erudition and research and probably had means of obtaining information with which we are unacquainted; we think therefore that as his statements have not yet been met by proofs of their incorrectness, or by counter-statements of greater weight, we are bound to accept them until additional light be thrown upon the subject. He tells us that remains of antique furnaces and ruins of a vase shop of classic times, with fragments of red and black wares and lamps marked with the letter G, were found in the locality known as the “Gabbice” where the Lanfranchi works were afterwards established in the 16th century, and where the earth is of fine quality. He traces the use of this earth in the time of the Goths, and states that it again revived under the government of the Malatesta; and that soon afterwards a mode of adorning churches was adopted by the insertion of discs of earthenware at first simply glazed with the oxide of lead, but that coloured ones were subsequently used.